Dena S. Davis: Genetic testing offers peek into the past and the future

February 08, 2013

When I was a child, I was fascinated by Norse mythology and especially by the story of the goddess Frigg, who, ignoring all warnings, looked into a magic well in which one could see the future. What she saw there was the death of her beloved son, Baldur. Determined not to let this happen, Frigg made every object and element in the world swear an oath not to harm her son, but she overlooked the innocuous mistletoe. A mischievous god, Loki, fashioned a piece of mistletoe into an arrow that killed Baldur.

Stories like this abound, with the twin messages that one is better off not knowing what the future holds and that one cannot avert one's fate in any case. Today, with the advent of increasingly cheap and fast gene typing, we don't need to be gods and goddesses to face the same question: Do we want to know what future our genes have in store for us?

Of course, even if we knew every bit of information in our entire genome, we couldn't really predict the future. Few genes are that black and white. Most simply confer higher or lower degrees of risk, with your individual outcome dependent on some combination of genetics and what scientists call the "environment," meaning everything that is not genetic, including a big dose of pure luck. After all, you may be at relatively high risk for developing Alzheimer's in your 70s, but that's not very relevant if you are killed in a car accident when you're 50.

Still, many people are fascinated to know whatever they can about their genetic makeup, including disease risk and ancestral heritage. Some people are just curious; others perhaps are trying to motivate themselves toward healthier behaviors. National Institutes of Health Director Francis Collins, upon discovering his relatively high genetic risk for Type II diabetes, got off his beloved motorcycle, started to walk more, and lost 20 pounds.

Today, you don't have to be a famous scientist or even have a doctor's prescription to find out a raft of information about your genome. For a modest financial outlay, you can spit in a container, send your saliva off to a private company, and log on to a secure Internet site to find out the results. We call this direct-to-consumer genetic testing, and it is very controversial.

Is it a wonderful new way to take our health into our own hands? Or is this sort of knowledge more scary than helpful? Should access to this information be treated like a drug, essentially under the control of a health professional who writes you the prescription and monitors the effects?

These companies claim that knowing more about your health risks will help you work with your doctor to figure out how to protect your health, but most doctors are woefully uneducated about genetics. With the average doctor's visit less than 20 minutes long, most primary care physicians don't really welcome the sight of a patient trailing a multipage printout of her genome.

Some of this, of course, is just pure fun. The Neanderthal Ancestry Lab of 23andMe promises to tell me what percentage of my genomes is directly descended from my Neanderthal ancestors. Since the average proportion of Neanderthal genes in a modern human is under 3 percent, I don't expect my results to have a big effect on my life.

But the company also promises to tell me if I share an ancestor with a famous figure "such as Marie Antoinette or Thomas Jefferson." I can certainly see myself swanning around, grandly proclaiming "Let them eat cake!" and sticking model ships in my hair.

I think Frigg regretted her visit to the magic well. Or maybe not. Did she feel some satisfaction that she had done her best to save her son, or did she feel guilt that she had overlooked the lowly mistletoe? Does knowing something about your genome help you feel some control in this complicated life or just complicate it further? At $99 for a (partial) peek into the well, many more of us are about to find out.

Dena S. Davis, presidential chair in health at Lehigh University, will speak about direct-to-consumer genetic testing at the Town Hall Lecture series at Bethlehem City Hall 7 p.m. Wednesday. The lecture, sponsored by Lehigh University's South Side Initiative, is free and open to the public.